CN106451934B

CN106451934B - Method for manufacturing stator of rotating electric machine and cassette coil for rotating electric machine

Info

Publication number: CN106451934B
Application number: CN201610644648.1A
Authority: CN
Inventors: 星名博
Original assignee: Toyota Motor Corp
Current assignee: Toyota Motor Corp
Priority date: 2015-08-10
Filing date: 2016-08-08
Publication date: 2019-12-24
Anticipated expiration: 2036-08-08
Also published as: US10320256B2; JP6288002B2; US11018543B2; US20170047828A1; CN106451934A; JP2017038474A; US20190245403A1; US20190245402A1

Abstract

The present invention relates to a method for manufacturing a stator of a rotating electric machine. The method comprises the following steps: forming a stator core; forming each cassette coil by concentrically winding a flat angle wire for a certain number of turns, each cassette coil being formed by applying a transformation amount to a winding shape of at least one turn with respect to an axis in a winding direction before being mounted on the teeth; mounting each cassette coil on each tooth while offsetting the amount of the shift; and forming a wound coil of the rotating electrical machine by connecting the winding terminal of one cassette coil with the winding terminal of the other cassette coil.

Description

Method for manufacturing stator of rotating electric machine and cassette coil for rotating electric machine

Technical Field

The present invention relates to a method for manufacturing a stator of a rotating electric machine and a cassette coil for a rotating electric machine using the method.

Background

As a winding method of a coil wound around a plurality of teeth of a stator of a rotating electrical machine, concentrated winding in which a coil of one phase is wound around one tooth and distributed winding in which a coil of one phase is wound across a plurality of teeth are known.

Japanese patent application publication No.2015-073386(JP 2015-073386A) describes that, as a stator of a three-phase rotating electrical machine, a coil unit formed by concentrically/concentratedly winding a coil wire composed of flat wires is mounted on each of a plurality of teeth of the stator, and end portions of the coil units in the same phase are connected to each other.

The concentrated winding coil can be prepared in advance as a coil unit around which a winding is wound, for example, so as to correspond to each tooth of the stator core. This is called a cassette coil. In order to assemble the cassette coil on the stator core, an assembly gap of a certain width is required. In the related art, in order to prevent the cassette coil from falling off from the stator core due to the assembly gap, another member having a claw portion or the like for fixing the cassette coil on the stator core is used.

Disclosure of Invention

The present invention provides a method for manufacturing a stator of a rotating electric machine capable of fixing a cassette coil on a stator core without using a special fixing member and a cassette coil for a rotating electric machine used for the method.

A method for manufacturing a stator of a rotating electric machine according to an aspect of the present invention includes: forming a stator core having teeth protruding radially inward from an annular stator yoke; forming each of the cassette coils by concentrically winding a flat angle wire for a certain number of turns, each of the cassette coils being formed by applying a transformation amount to a winding shape of at least one turn with respect to an axis in a winding direction before being mounted on one of the teeth; mounting each of the cassette coils on each of the teeth while canceling out the shift amount; and forming a winding coil in the rotary electric machine by connecting winding terminals of the cassette coil to each other.

According to the method for manufacturing the stator of the rotary electric machine having the above-described configuration, the cassette coil is used which is formed by concentrically winding a flat wire and by applying a certain amount of transformation to the winding shape of at least one turn with respect to the axis in the winding direction before being mounted on one of the teeth. The cassette coil has the characteristics of a coil spring and can have appropriate coil spring elasticity by using a flat wire thereto. By utilizing this coil spring elasticity, the cassette coil can be mounted while applying a reaction force of elasticity due to cancellation of the amount of conversion to each tooth.

A method for manufacturing a stator of a rotating electric machine according to another aspect of the present invention includes: forming a stator core having teeth protruding radially inward from an annular stator yoke; forming each of the cassette coils by concentrically winding a flat angle wire by a certain number of turns, each of the cassette coils being formed by applying a transformation amount to a winding shape of at least one turn with respect to an axis in a winding direction before being mounted on the stator core; disposing each of the insulators on an outer peripheral side surface of each of the teeth, the insulators having a cylindrical shape and being held between an inner peripheral side surface of the cassette coil and an outer peripheral side surface of each of the teeth that opposes the inner peripheral side surface of the cassette coil, and the insulators being provided with a step on an outer side surface of the cylindrical shape that corresponds to the inner peripheral side surface of each turn of the rectangular wire; bringing an inner peripheral side surface of each turn of the rectangular wire into contact with the step of each insulator while canceling out the shift amount, and mounting each cassette coil; and forming a specific winding coil in the rotary electric machine by connecting winding terminals of the cassette coil to each other.

According to the method for manufacturing the stator of the rotary electric machine having the above-described configuration, the cassette coil is mounted on the stator core in such a manner that the inner peripheral side surface of each turn of the rectangular wire of the cassette coil is embedded on the step of the insulator. Thus, the same elastic reaction force as the elastic force of the coil spring using the flat wire can be reliably applied to the insulator.

In the method for manufacturing a stator of a rotary electric machine according to the aspect of the invention, the amount of change in the shape of the winding may be a magnitude of a torsion angle with respect to an axis in the winding direction.

According to the method for manufacturing the stator of the rotating electric machine having the above-described configuration, the specific torsion angle is applied to the winding shape of at least one turn about the axis in the winding direction before mounting on the teeth or the insulator. Thus, an elastic reaction force generated due to the cancellation of the torsion angle of the wire winding can be applied to the tooth or the insulator.

In the method for manufacturing a stator of a rotary electric machine according to the aspect of the invention, the transformation amount of the winding shape may be a displacement amount in a circumferential direction of the stator core with respect to the axis in the winding direction.

According to the method for manufacturing the stator of the rotary electric machine having the above-described configuration, the specific displacement amount is applied to the winding shape of at least one turn in the circumferential direction of the stator core with respect to the axis in the winding direction before mounting on the teeth or the insulator. Thus, an elastic reaction force generated due to the offset of the displacement amount of the wire winding can be applied to the teeth or the insulator.

A cassette coil for a rotary electric machine according to an aspect of the present invention includes a flat wire. The flat wires are concentrically wound by a certain number of turns. The flat wire is wound by applying a transformation amount to a winding shape of at least one turn with respect to an axis in a winding direction before being mounted on a stator core of a stator of the rotating electric machine.

According to the cassette coil for a rotary electric machine having the above-described configuration, the cassette coil is formed by applying a certain transformation amount to the winding shape of at least one turn with respect to the axis in the winding direction before being mounted on the stator core. The cassette coil has the characteristics of a coil spring and can have appropriate coil spring elasticity by using a flat wire thereto. By utilizing this coil spring elasticity, the cassette coil can be mounted while applying a reaction force of elasticity due to the cancellation of the conversion amount to the stator core.

According to the aspect of the invention, the cassette coil can be fixed to the stator core without using a special fixing member.

Drawings

Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which like reference numerals represent like elements, and wherein:

fig. 1 is a plan view of a stator of a rotary electric machine manufactured by a method for manufacturing a stator of a rotary electric machine in an embodiment according to the present invention, the stator being viewed from a lead wire side in an axial direction from which power wires are drawn;

fig. 2 is a perspective view of a cassette coil wound around one tooth and viewed from the radially inner side with the lead side as the lower side in fig. 1;

FIG. 3A is a view of the stator yoke removed from FIG. 2;

FIG. 3B is a perspective view of the insulator pulled from FIG. 3A;

fig. 3C is a perspective view of the cassette coil before being wound around the stator core in fig. 3A;

fig. 3D is a perspective view of a state in which the cassette coil in fig. 3C is mounted on the stator core via the insulator in fig. 3B;

fig. 4 is a flowchart showing respective flows of a method for manufacturing a stator of a rotary electric machine in an embodiment according to the present invention;

fig. 5A is a view showing a method for winding a cassette coil of the related art as a comparative example;

fig. 5B is a view illustrating a method for winding a cassette coil for a rotary electric machine according to an embodiment of the present invention;

fig. 6 is a view showing another method for winding a cassette coil for a rotary electric machine according to an embodiment of the present invention;

fig. 7A is a view showing a reaction force generated when the cassette coil in fig. 5B is mounted on a stator core; and

fig. 7B is a view showing a reaction force generated when the cassette coil in fig. 6 is mounted on the stator core.

Detailed Description

Embodiments according to the present invention will be described in detail below with reference to the accompanying drawings. A stator for a rotary electric machine mounted in a vehicle will be described below as a stator for a rotary electric machine manufactured by a method for manufacturing a stator for a rotary electric machine. However, it should be understood as an example that is set forth for illustrative purposes. The application of the stator of the rotating electric machine may not necessarily be a vehicle installation as long as the concentrically wound cassette coil is used. The shape, size, number of teeth, number of turns, material, and the like, which will be described below, are merely illustrative for the purpose of description and thus may be appropriately changed according to the specification of the stator of the rotary electric machine. In the following description, like members are denoted by like reference numerals throughout the drawings, and a description thereof will not be repeated.

Fig. 1 is a view of the configuration of a rotary electric machine stator 10 for a rotary electric machine mounted in a vehicle, as a stator of a rotary electric machine manufactured by a method for manufacturing a stator of a rotary electric machine to be described below. Unless otherwise indicated, the rotary electric machine stator 10 will be referred to as the stator 10 hereinafter. Power wires 18 to be connected to a drive line, not shown, are led out from the stator 10. The rotary electric machine using the stator 10 is a motor generator that functions as a motor during power running of the vehicle and as a generator during braking of the vehicle by control of the drive line, and is a three-phase synchronous rotary electric machine. The rotating electric machine is configured by including: a stator 10 shown in fig. 1 as a stator; and a rotor as an annular rotor disposed radially inside the stator 10 with a certain gap provided therebetween. The rotor is not shown in fig. 1.

Fig. 1 is a top view of the stator 10 as viewed from the lead side in the axial direction. Of the two sides of the stator 10 in the axial direction, the lead side is the side from which the power wires 18 are drawn from the stator 10. The opposite side of the lead side in the axial direction is the counter-lead side. Fig. 1 shows the circumferential, radial and axial directions of the stator 10. The two-sided directions in the circumferential direction are a right-hand direction and a left-hand direction in a top view of the stator 10 viewed from the lead wire side. Hereinafter, the right-handed direction will be referred to as a clockwise direction, and the left-handed direction will be referred to as a counterclockwise direction. The both side directions in the radial direction are the inside direction and the outside direction of the stator core 12. The two-sided directions in the axial direction are the lead-side direction and the reverse lead-side direction.

The stator 10 is constituted by including a stator core 12, a cassette coil 14 mounted on the stator core 12, and an insulator 16 disposed between the stator core 12 and the cassette coil 14.

The stator core 12 is an annular magnetic member and includes an annular stator yoke 20 and a plurality of teeth 22 that protrude radially inward from the stator yoke 20. The space between adjacent teeth 22 is a slot 24. The teeth 22 are projections on which the cassette coil 14 is mounted and thus serve as magnetic poles.

Such a stator core 12 is formed by laminating a plurality of annular magnetic thin plates 28 (refer to fig. 2), and each annular magnetic thin plate 28 is molded in a specific shape so as to provide the stator yoke 20 and the teeth 22 and form the slots 24. Both surfaces of the magnetic thin plate 28 are subjected to electrical insulation treatment. An electromagnetic steel sheet can be used as the material of the magnetic thin plate 28. Instead of the laminate of the magnetic thin plates, a product in which magnetic powder is integrally molded in a specific shape may be used.

The cassette coil 14 is a coil wound concentrically and formed by winding a winding wire of one phase around one tooth 22 by a certain number of turns. The cassette coils 14 of different phases are arranged in one slot 24 between adjacent teeth 22.

Such a box-type coil 14 is a coil unit formed by winding a wire with an insulating film attached thereto by a certain number of turns with a certain bobbin and removing the wound wire from the bobbin. The wire with the insulating film is not directly wound around the teeth 22 of the stator 10 by using the slots 24 as spaces located on both sides of the teeth 22. In contrast, the cassette coil 14, which is a single coil body as a separate member from the stator core 12, is embedded and mounted on the teeth 22. The cassette coil 14 is a single coil body formed by using a wire with an insulating film attached thereto. The cassette coil 14 is a single coil body formed by a method described below in which no bobbin or the like is used.

As the element wire of the insulating film-attached lead wire used for the cassette coil 14, a copper wire, a copper-tin alloy wire, a silver-plated copper-tin alloy wire, or the like can be used. As the element wire, a rectangular wire having a substantially rectangular cross-sectional shape is used. As the insulating film, an enamel film made of polyamide-imide is used. Instead of this material, polyester-imide, polyimide, polyester, dimethoxymethane, or the like can be used.

One unit of the cassette coil 14 is mounted on each tooth 22 of the stator core 12. In the example of fig. 1, the stator core 12 has five U-phase teeth 22, five V-phase teeth 22, and five W-phase teeth 22, and one unit of the cassette coil 14 is mounted on each of the fifteen teeth 22. In fig. 1, the teeth 22 on which the cassette coils 14 are respectively mounted are shown as U1 to U5 for the U phase, V1 to V5 for the V phase, and W1 to W5 for the W phase.

In the three-phase synchronous rotating electrical machine, groups of U-phase coils, V-phase coils, and W-phase coils are arranged in order in the circumferential direction of the stator core 12. For example, five U-phase box coils 14 are arranged along the circumferential direction of the stator core 12 while being spaced apart from each other at intervals of three teeth. Similarly, five V-phase box coils 14 are also arranged in the circumferential direction of the stator core 12 in a state of being separated from each other at intervals of three teeth, and five W-phase box coils 14 are also arranged in the circumferential direction of the stator core 12 in a state of being separated from each other at intervals of three teeth.

Each cassette coil 14 has a winding start end and a winding termination end of the winding wire. Among the five cassette coils 14 of the same phase arranged in the circumferential direction of the stator core 12, the winding start end of the first cassette coil 14 is connected to the power wire 18. The winding terminal end of the first cassette coil 14 is connected with a winding start end of the second cassette coil 14 separated from the first cassette coil 14 by three teeth intervals using a jumper wire. The winding terminal end of the second cassette coil 14 is connected with a winding start end of a third cassette coil 14 separated from the second cassette coil 14 by three teeth intervals by a jumper wire. This process is repeated, and the winding terminal end of the last fifth cassette coil 14 is connected to the winding terminal ends of the respective fifth cassette coils 14 of the other two phases and serves as the neutral point N. In fig. 1, the jumper wires for the respective phases are distinguished from each other and are shown as a U-phase jumper wire 26U, V-phase jumper wire 26V and a W-phase jumper wire 26W.

For example, with respect to the U-phase coil, the U terminals of the three power wires 18 are connected to the winding start end of the cassette coil 14 of U1. The winding terminating end thereof is connected to the winding starting end of the cassette coil 14 of U2 with the jumper wire 26U. The winding-terminating end of the cassette coil 14 of U2 and the winding-starting end of the cassette coil 14 of U3 are connected with another jumper wire 26U. This process is repeated, and the winding terminal end of the cassette coil 14 of U5 serves as the neutral point N. The same is true for the V-phase winding coil and the W-phase winding coil. As described, the winding start end and the winding termination end, which are the winding termination ends of the cassette coil 14, are connected to each other by a specific connection method, thereby forming a three-phase wound coil in the rotary electric machine. Thus, five U-phase magnetic poles corresponding to U1 to U5, five V-phase magnetic poles corresponding to V1 to V5, and five W-phase magnetic poles corresponding to W1 to W5 are formed.

The insulator 16 is an insulator having a cylindrical shape held between an inner peripheral side surface of the cassette coil 14 and an outer peripheral side surface of the tooth 22 facing the inner peripheral side surface of the cassette coil 14. The insulator 16 is fixed to the stator core 12 by fixing means such as adhesion. A product formed by molding a sheet having electrical insulation into a specific shape may be used as such an insulator 16. As the sheet having electrical insulation, a plastic film may be used in addition to paper. Details of the insulator 16 will be described below. Note that, in the case where the electrical insulating property of the insulating film of the cassette coil 14 is sufficient, the insulator 16 may not be used. Unless otherwise indicated, the insulator 16 will be used hereinafter.

The concentrically wound coil is wound in a specific loop shape while the wire is bent. Therefore, according to the rigidity of the wire, an elastic reaction force urging the coil back to the original wire shape is applied in the circumferential direction and the radial direction, similar to the coil spring. In the present embodiment, the cassette coil 14 is fixed to the stator core 12 as a coil spring by positively utilizing the elastic reaction force.

Fig. 2 is a view in which the magnetic pole 30 corresponding to U4 in fig. 1 is taken out, the axial direction is reversed up and down, and the lead side is shown as the lower side of the paper surface to illustrate the winding method.

The teeth 22 protrude radially inward from the stator yoke 20, and have a rectangular cross-sectional shape parallel to a circumferential surface. The stator yoke 20 and the teeth 22 are formed by laminating magnetic thin plates 28 in the same shape. Therefore, the height dimensions of the stator yoke 20 and the teeth 22 in the axial direction are the same. Different types of electromagnetic steel plates may be used for the stator yoke 20 and the teeth 22 so as to be different in height dimension from each other, depending on the specifications of the stator 10.

The cassette coil 14 shown in fig. 2 is embedded on the outer side face of the insulator 16. Therefore, in order to distinguish the cassette coil 14 from the cassette coil 60 (see fig. 3C) which is a single coil before mounting, the cassette coil 14 may be referred to as the cassette coil 14 after mounting. The width W of the cassette coil 14₀And has a thickness t₀And the cassette coil 14 is wound around the axis in the winding direction with the thickness direction being the radial direction by a certain number of turns. The winding shape of each turn of the flat wire is a rectangular ring shape with the four corners rounded. The axis in the winding direction is an axis parallel to the radial direction and an axis passing through the center of a rectangular ring shape as a winding shape of each turn. Of flat line (width W)₀Thickness t₀) Falling within the range of 1 or more to about 3. According to the specification of the stator 10, of a flat line (width W)₀Thickness t₀) May have different values than the above.

The winding start end 32 of the mounted cassette coil 14 is located in the vicinity of the intersection of the lead-wire-side end of the tooth 22 and the radially outer end of the tooth 22. The flat wire is wound around the axis in the winding direction from the winding start end 32 by 7 turns in the counterclockwise direction. The axis in the winding direction is an axis parallel to the radial direction. The winding termination end 34 after 7 turns is located in the vicinity of the intersection of the lead-wire-side end portion and the radially inner-side end portion of the tooth 22. Of four sides of the rectangular ring shape which is the shape of the coil of each turn, two sides are parallel to the axial direction, and the other two sides are parallel to the circumferential direction. Note that the radially inner end of the tooth 22 and the radially inner end of the insulator 16 protrude further radially inward from the radially inner end of the cassette coil 14.

Fig. 3A to 3D show the relationship between the teeth 22, the insulator 16, the cassette coil 14 after being mounted on the insulator 16, and the cassette coil 60 before being mounted on the insulator 16.

Fig. 3A is a view in which the magnetic poles 30 of the stator yoke 20 in fig. 2 are not shown, and corresponds to a view in which the insulator 16 and the cassette coil 14 are assembled on the teeth 22. Fig. 3B is a perspective view of the insulator 16 obtained by exploded-view fig. 3A. Fig. 3C is a perspective view of the cassette coil 60 before installation. Fig. 3D is a perspective view of the mounted cassette coil 14 obtained by exploded-view fig. 3A. In fig. 3A to 3C, positions corresponding to the insulators 16 are shown by connecting two-dot chain lines. In fig. 3C and 3D, positions corresponding to the winding start end 32 and the winding termination end 34 are shown by connecting broken lines.

The insulator 16 shown in fig. 3B has a back plate portion 40 for electrically insulating the cassette coil 14 and the stator yoke 20 from each other. Further, the insulator 16 has a side wall plate portion 42 which is connected to the back panel portion 40 and insulates an inner peripheral side surface of the cassette coil 14 and an outer peripheral side surface of the tooth 22, which is opposed to the inner peripheral side surface of the cassette coil 14, from each other. The back panel portion 40 has an opening through which the tooth 22 passes, and the side wall panel portion 42 is provided by being connected to an edge of the opening. The side wall plate 42 is a cylindrical member that extends along the outer peripheral side surface of the tooth 22.

The teeth 22 are projections whose cross-sectional shape perpendicular to the radial direction is rectangular. In the range of the rectangular sectional shape in which the cassette coil 14 is mounted, the sides in the circumferential direction at the tip end portions of the teeth 22 are shorter than the sides in the circumferential direction in the root portions located on the stator yoke portion 20 side. That is, the teeth 22 are tapered in the range where the cassette coil 14 is mounted. In the radial direction, in a portion protruding radially inward from the range where the cassette coil 14 is mounted, the length of the tooth 22 in the circumferential direction is constant. Corresponding to this shape of the teeth 22, the side wall plate portion 42 of the insulator 16 has a shape that tapers toward the distal end side in the range where the cassette coil 14 is mounted. In a portion protruding from a range where the cassette coil 14 is mounted to the distal end side, the length of the insulator 16 in the circumferential direction is constant.

In the mounted state, the inner peripheral side surface of the rectangular wire of each turn of the box coil 14 is in contact with the outer side surface of the side wall plate 44 positioned on the clockwise side in the circumferential direction and the outer side surface of the side wall plate 46 positioned on the counterclockwise side in the side wall plate portion 42 of the insulator 16. The insulator 16 is tapered toward the distal end side in the range where the cassette coil 14 is mounted. Therefore, when the flat wire having a substantially rectangular cross-sectional shape is in contact with the outer side surface of the insulator 16 which is tapered, a gap is formed between the inner peripheral side surface of the flat wire and the outer side surface of the insulator 16. In order to prevent the occurrence of the gap, a step-like step 48 is provided, the shape of which is matched with the inner peripheral side surface of each turn of the rectangular wire. In this way, when the cassette coil 14 is mounted, the flat wires of the turns of the cassette coil 14 are arranged and disposed along the steps 48 on the outer side surfaces of the side wall plates 44, 46 of the insulator 16 without generating unnecessary gaps.

In the side wall plate portion 42 of the insulator 16, a bulging portion 50 bulging toward the lead side in the axial direction and a bulging portion 52 bulging toward the opposite lead side are provided to secure a bending radius used when a flat wire is bent in a rectangular ring shape. The inner peripheral side surface of the flat wire of each turn of the cassette coil 14 is in contact with the bulging outer side surfaces of the bulging portions 50, 52.

In the cassette coil 60 before installation shown in fig. 3C, a flat wire is wound around the axis in the winding direction from the winding start end 32 by 7 turns in the counterclockwise direction, and this is the same as the cassette coil 14 after installation. (E-E) is an axis in the winding direction and is an axis parallel to the radial direction and passing through the center of the winding shape of the flat line of each turn. The axis (E-E) in the winding direction is also an axis parallel to the radial direction and passing through the center of the cross-sectional shape of the tooth 22 perpendicular to the radial direction. In the cassette coil 60 before installation, when 7 turns are wound around the axis (E-E) in the winding direction, the winding form of each turn is twisted around the axis (E-E) in the winding direction by a specific twist angle Δ θ. The twist angle Δ θ is an angle at which the coil shape is twisted at a small angle around the axis (E-E) in the winding direction when the cassette coil 60 is regarded as a coil spring. The torsion angle Δ θ is an angle of several degrees and thus is different from a rotation angle having an angle of 360 degrees for 1 cycle. The twisting angle Δ θ is an angle at which the winding shape of each turn is constant and the entire winding shape is twisted around the axis (E-E) in the winding direction. The twist angles Δ θ in 7 turns are different from each other.

With respect to the mounted cassette coil 14, the torsion angle Δ θ is equal to 0 degrees. Therefore, the torsion angle Δ θ corresponds to an angular difference around the axis (E-E) in the winding direction between the winding shape of each turn in the cartridge coil 14 after installation and the winding shape of each turn in the cartridge coil 60 before installation.

Accordingly, the torsion angle Δ θ will be explained by comparing the cartridge coil 60 before mounting and the cartridge coil 14 after mounting. Fig. 3D is a view in which the cassette coil 14 mounted on the magnetic pole 30 is taken out. When removed from the magnetic pole 30, the cassette coil 14 returns to the state of the cassette coil 60 before installation in fig. 3C. Note that fig. 3D shows the cassette coil 14 in a state of being mounted on the magnetic pole 30.

In fig. 3D, a diagonal line is added to a part of the rectangular wire winding shape 36 in the innermost turn in the radial direction among 7 turns. The coil shape 36 includes: a side having a winding end 34 and parallel to the circumferential direction; and a side 38 preceding the side and parallel to the axial direction. The angle between these two sides is 90 degrees.

The two-dot chain line in fig. 3C indicates a portion corresponding to the coil shape 36 in fig. 3D, which includes a side having the coil termination end 34 and parallel to the circumferential direction and a side 38 preceding the side and parallel to the axial direction. The winding shape 62 of the flat wire in the radially innermost turn among 7 turns of the cassette coil 60 before being mounted on the magnetic pole 30 includes: a side having a winding end 64 and parallel to the circumferential direction; and a side 66 directly in front of the side and parallel to the axial direction.

Here, the twist angle Δ θ is related to the winding shape of the flat wire in the radially innermost turn among the 7 turns. With respect to the side parallel to the axial direction, the twist angle Δ θ is an angular difference generated when the side 38 of the cassette coil 14 after installation and the side 66 of the cassette coil 60 before installation overlap each other. With respect to the side parallel to the circumferential direction, the twist angle Δ θ is an angular difference generated when the side having the winding termination end 34 of the cassette coil 14 after installation and the side having the winding termination end 64 of the cassette coil 60 before installation overlap each other. The coil shape 62 does not change from the coil shape 36 even when the torsion angle Δ θ is applied. The relationship of "the winding shape 62 ═ the winding shape 36" remains the same, and the winding shape 62 rotates only at a twist angle Δ θ, which is a slight angle in a plane in the circumferential direction.

The twist angles Δ θ in 7 turns of the flat line are different from each other. If 7 turns of the flat line are distinguished from each other, the first turn including the winding start end 32 is set to (N ═ 1) and the seventh turn including the winding end 64 is set to (N ═ 7), so that the twist angle Δ θ of the (N ═ 1) turn is minimum and the twist angle Δ θ of the (N ═ 7) turn is maximum. In the example of fig. 3C, the twist angle Δ θ (N ═ 1) of the first turn is 0 degree, and the twist angle Δ θ (N ═ 7) of the seventh turn is about 10 degrees. The twist angle is gradually increased in the range of 0 to 10 degrees for the second to sixth turns.

The cassette coil 60 before being mounted is wound around an axis (E-E) in the winding direction in a state where a specific torsion angle Δ θ is applied to the winding shape of each turn of the flat wire, and is fixed and formed in such a shape. As a method for fixing the shape, a suitable press molding method can be used. The cassette coil 60 before installation is mounted on the teeth 22 via the insulator 16 in fig. 3B. At this time, the respective turns of the flat wire are attached in such a manner as to be in contact with the step 48 of the insulator 16.

Since the cassette coil 60 has elasticity like a coil spring, the twist angle of the winding wire of each turn is offset by the installation. For example, in the case of the seventh turn, the winding portion having the winding shape 62 to which the torsion angle Δ θ is applied is mounted on the tooth 22 via the insulator 16. Accordingly, the seventh turn is elastically returned as the winding wire portion having the winding wire shape 36. The elastic reaction force at this time is applied to the step 48 of the insulator 16. In this way, the cassette coil 14 is fixed to the stator core 12 via the insulator 16 without using a special fixing member.

A method for manufacturing the stator 10 of the above-described configuration will be described in detail below with reference to fig. 4 and subsequent drawings. Fig. 4 is a flowchart showing respective flows of a method for manufacturing the stator 10. Here, the stator core 12 is formed (S10). The stator core 12 is formed by laminating a specific number of annular magnetic thin plates 28 molded in a specific shape. An electromagnetic steel sheet having both surfaces subjected to electrical insulation treatment is used as the magnetic thin sheet 28.

Next, the insulator 16 having the step 48 described with reference to fig. 3B is disposed in each tooth 22 of the stator core 12 (S12). S12 is performed by embedding the insulator 16 from the tip side of each tooth 22.

Simultaneously with or before S10 and S12, the cartridge coil 60 before mounting is formed (S14). In S14, the cassette coil 60 before installation is formed by winding each turn using a flat angle wire as described with fig. 3C and while the twist angle Δ θ of the winding wire of each turn with respect to the axis (E-E) in the winding direction during winding around the teeth 22 is shifted from each other.

Fig. 5A and 5B are views comparing a method for forming a cassette coil before installation with the related art. In these views, the teeth have the same cross-section in the radial direction.

Fig. 5A is a view of one example of a method for manufacturing the concentrically wound cassette coil 15 in the related art. In the related art, the bobbin 70 having a predetermined sectional shape is used for winding. The bobbin 70 is rotatable about an axis 72 in the winding direction. Here, the winding start end 32 of the rectangular wire is fixed at an appropriate position of the bobbin 70 and arranged along the outer circumference of the bobbin 70. Then, the bobbin 70 is rotated in the direction of the arrow in fig. 5A about the axis in the winding direction while feeding the flat wire in the feeding direction 74 indicated by the arrow. The feeding in the feeding direction 74 includes feeding in the radial direction and feeding in the circumferential direction in accordance with the progress of winding. Thus, the rectangular wire is wound in a spiral shape along the outer periphery of the bobbin 70. A winding guide groove having a spiral shape may be provided in the bobbin 70.

In the method for forming the cassette coil 60 before installation described with fig. 3C, a bobbin for twist formation having a twist angle Δ θ for each turn is prepared. The respective turns of the flat wire are wound in a similar method to that in fig. 5A by using a bobbin for twist formation. In this way, the cartridge coil 60 before installation described using fig. 3C can be formed.

Fig. 5B is a view of another method for applying the twist angle Δ θ to the coil winding shape of each turn. The cassette coil 61 in fig. 5B is formed by performing an additional process on the cassette coil 15 formed by the method shown in fig. 5A. As this additional step, the torsion support shaft 76 is applied to one of the rounded portions at the corner portions of the cassette coil 15, and the winding shape of each turn is wound around the torsion support shaft 76 at a specific torsion angle Δ θ. Here, "twist" means that the coil shape is rotated at a slight angle and stopped at a rotated position as described with fig. 3C. In the example of fig. 3C, the twist angle Δ θ of the seventh turn is about 10 degrees. As a method for fixing the twisted shape, an appropriate press molding method can be used.

Each of the cartridge coils 60 and 61 before being mounted is formed by applying a twist angle Δ θ to a winding shape of each turn. However, a method different from the above-described method may be employed. For example, the cassette coil before installation may be formed by a method in which a certain amount of transformation of the initial twist of the winding shape of each turn with respect to the axis in the winding direction is applied. For the cassette coil 63 in fig. 6, the cassette coil 15 formed by the method shown in fig. 5A is used, and a certain displacement amount Δ P is applied to the winding shape of each turn in the circumferential direction as a certain shift amount. The displacement deltap in these turns are again different from each other. The displacement amount Δ P of the first (N ═ 1) turn from the winding start end 32 is the smallest. The displacement amount Δ P increases as N, which indicates the number of turns, increases, and the displacement amount Δ P of the seventh (N-7) turn is the largest. As a method for fixing the shape to which the displacement amount is applied, an appropriate press molding method can be used.

In the above description, the torsion angle Δ θ is set to an angle in the clockwise direction when viewed from the inside of the cassette coils 60, 61 in the radial direction; however, it may be set to an angle in the counterclockwise direction. In addition, the displacement amount Δ P of the cassette coil 63 is set to the displacement amount in the clockwise direction in the circumferential direction; however, it may be set as the amount of displacement in the counterclockwise direction in the circumferential direction. Further, the torsion angle Δ θ and the displacement amount Δ P can be combined. In the above description, the twist angle Δ θ and the displacement amount Δ P in these turns are different from each other again; however, the torsion angle Δ θ and the displacement amount Δ P may be different in a part of each turn from the rest of the part of each turn. The twist angle Δ θ and the displacement amount Δ P are applied to the winding shape of at least one turn. For example, the torsion angle Δ θ or the displacement amount Δ P may be applied only to the seventh turn located at the radially innermost side. Note that the number of turns is 7 in the above description; however, the number of turns may be other than 7.

Next, returning to fig. 4, the cassette coil 60 formed in S14 is mounted on the stator core 12 (S16). Here, the cassette coil 60 is mounted on the insulator 16 disposed in the stator core 12 in S12. Instead of the cassette coil 60, a cassette coil 61 in fig. 5B or a cassette coil 63 in fig. 6 may be used. In the cassette coil 60 which remains the same as the cassette coil formed in S12, the coil shape of each turn is applied with a certain transformation amount and has an initial twist. The cassette coil 60 is mounted in the following manner: the cassette coil 60 is inserted from the tip side of the teeth 22 and the insulator 16, and the inner peripheral side surface of each turn of the rectangular wire is aligned and brought into surface contact with the step 48 on the outer side surface of the insulator 16 while canceling the shift of the coil shape of each turn.

Fig. 7A is a view of an action exerted when the cassette coil 60 is mounted on the outer side surface of the insulator 16 in a state where the torsion angle Δ θ, which is a change amount of the coil shape of each turn, is cancelled. With respect to the cartridge coil 60 before mounting, twist angle cancellation (- Δ θ) is performed thereon from a state having a twist angle Δ θ. Thus, the cassette coil 60 becomes the mounted cassette coil 14. The cassette coil 60 has a characteristic as a coil spring. Therefore, the cassette coil 60 is elastically deformed by the torsion angle cancellation at (- Δ θ), and its elastic reaction force is applied to the step 48 of the insulator 16. With this elastic reaction force, the cassette coil 14 is fixed to the insulator 16 and to the stator core 12. The same applies to the cassette coil 61.

Fig. 7B is a view of the action exerted when the cassette coil 63 is mounted on the outer side face of the insulator 16. With respect to the cassette coil 63 before mounting, the displacement amount cancellation of (- Δ P) is performed thereon from the state having the displacement amount Δ P. Thus, the cassette coil 63 becomes the mounted cassette coil 14. The cassette coil 63 has a characteristic as a coil spring. Therefore, the cassette coil 63 is elastically deformed due to the offset amount of (- Δ P) and its elastic reaction force is applied to the step 48 of the insulator 16. With this elastic reaction force, the cassette coil 14 is fixed to the insulator 16 and to the stator core 12.

The elastic reaction force is a force that attempts to cancel out the elastic deformation due to the cancellation of the specific conversion amount. In both cases of fig. 7A and 7B, the direction of the specific shift amount is the counterclockwise direction with respect to the circumferential direction. Therefore, the direction of the elastic deformation that cancels the amount of transformation is the clockwise direction with respect to the circumferential direction. Therefore, the direction of the elastic reaction force, which is the direction along which the elastic deformation tries to be cancelled, is the counterclockwise direction with respect to the circumferential direction. This elastic reaction force in the counterclockwise direction with respect to the circumferential direction is applied to the insulator 16 through the side located in the clockwise direction with respect to the circumferential direction among the two sides parallel to the axial direction of the winding shape of the cassette coil 14. Fig. 7A shows an elastic reaction force 80, while fig. 7B shows an elastic reaction force 82. By these elastic reaction forces 80, 82, the cassette coil 14 is fixed to the insulator 16 and to the stator core 12.

The magnitude of the elastic reaction forces 80, 82 required to fix the cassette coil 14 to the stator core 12 is specified in accordance with the specifications of the rotary electric machine such as the working environment. The width W of the flat line is set to generate elastic reaction forces 80, 82 of predetermined magnitude₀And a thickness t₀And the rigidity, winding shape, number of turns, torsion angle Δ θ, displacement amount Δ P, and the like of the material of the flat wire.

Returning to fig. 4, the step of S16 is performed for each insulator 16 fitted to each tooth 22 of the stator core 12. When the process in S16 is completed for all the teeth 22, as shown in fig. 1, the winding terminals of the cassette coil 14 are connected to each other by a specific connection method, and a specific winding coil in the rotary electric machine is formed (S18).

In the above description, the insulator 16 is used. However, in the case where the electrical insulating property of the cassette coil 14 is sufficient and the use of the insulator 16 is not required, the process in S12 is omitted. In S16, the cartridge coil 60 and the like before being mounted are directly mounted on the outer peripheral surface of the tooth 22. In this case, the elastic reaction force generated by the cancellation of the specific conversion amount is directly applied from the cassette coil 14 to the teeth 22. Thus, the cassette coil 14 is fixed to the teeth 22 of the stator core 12.

Here, this embodiment will be generalized. The method for manufacturing a stator of a rotating electric machine includes the steps of: forming a stator core having a plurality of teeth; forming a cassette coil by using a flat wire and concentrically winding the same by a certain number of turns, the cassette coil being formed by applying a certain transformation amount to a winding shape of at least one turn with respect to an axis in a winding direction before being mounted on a stator core; disposing an insulator on an outer peripheral side surface of the tooth, the insulator having a cylindrical shape held between an inner peripheral side surface of the cassette coil and an outer peripheral side surface of the tooth facing the inner peripheral side surface of the cassette coil and provided with a step on an outer side surface of the cylindrical shape corresponding to an inner peripheral side surface of each turn of the rectangular wire; and bringing the inner peripheral side surface of each turn of the rectangular wire into contact with the step of the insulator while canceling the shift amount, and mounting the cassette coil.

Claims

1. A method for manufacturing a stator of a rotary electric machine, the stator including a stator core and a wire winding coil, the wire winding coil including a cassette coil, the stator core including teeth that protrude radially inward from an annular stator yoke portion, the method characterized by comprising:

forming the stator core;

forming each of the cassette coils by concentrically winding a flat angle wire for a certain number of turns, each of the cassette coils being formed by applying a transformation amount to a winding shape of at least one turn with respect to an axis in a winding direction before being mounted on the teeth;

mounting each of the cassette coils on each of the teeth while canceling out the shift amount; and

the winding coil is formed by connecting a winding terminal of one of the cassette coils with a winding terminal of the other of the cassette coils.

2. The method of claim 1, wherein the step of removing the metal oxide layer comprises removing the metal oxide layer from the metal oxide layer

The change amount of the winding shape is a magnitude of a torsion angle of the winding shape with respect to an axis along the winding direction.

3. The method of claim 1, wherein the step of removing the metal oxide layer comprises removing the metal oxide layer from the metal oxide layer

The transformation amount of the winding shape is a displacement amount of the winding shape along a circumferential direction of the stator core with respect to an axis in the winding direction.

4. A method for manufacturing a stator of a rotary electric machine, the stator including a stator core, a wire winding coil, and insulators, the wire winding coil including cassette coils, the stator core including teeth that protrude radially inward from an annular stator yoke portion, each of the insulators being held between an inner peripheral side surface of each of the cassette coils and an outer peripheral side surface of each of the teeth that opposes the inner peripheral side surface of each of the cassette coils, each of the insulators having a cylindrical shape, and each of the insulators including, on the outer peripheral side surface, a step that corresponds to the inner peripheral side surface of the cassette coil, the method characterized by comprising:

forming the stator core;

forming each of the cassette coils by concentrically winding a flat angle wire by a certain number of turns, the cassette coils being formed by applying a transformation amount to a winding shape of at least one turn with respect to an axis in a winding direction before being mounted on the stator core;

disposing each of the insulators on an outer peripheral side surface of each of the teeth;

bringing an inner peripheral side surface of each turn of the rectangular wire into contact with the step of each insulator while canceling out the shift amount, and mounting each cassette coil; and

5. The method of claim 4, wherein the step of removing the metal oxide layer comprises removing the metal oxide layer from the metal oxide layer

6. The method of claim 4, wherein the step of removing the metal oxide layer comprises removing the metal oxide layer from the metal oxide layer

7. A cassette coil for a rotary electric machine including a stator having a stator core, the cassette coil characterized by comprising:

concentrically winding a specific number of turns of a flat angle wire wound by applying a specific transformation amount to a winding shape of at least one turn with respect to an axis in a winding direction before being mounted on the stator core, so that the cassette coil can be mounted on the stator core while offsetting the transformation amount.